2.6 Calculations
The bare soil area consisted of all bare soil patches, and the vegetated surface area was estimated by the plot areas minus the bare soil areas. The bare soil area in the disturbed plot was estimated by adding all bare soil patch areas. In each undisturbed plot, bare soil areas were considered zero, and the vegetated surface area was considered 100%.
The palatable plant biomass was calculated by the following equation:GB =Bqδva , whereGB , Bq and δva were the palatable plant biomass at the plot, palatable plant biomass at the quadrat scale (g m-2) and vegetated surface area, respectively. The plant species richness in a quadrat (1 m×1 m) was measured by the species number of each quadrat. Soil water storage was performed using the method recommended by Jia et al. (2020). The soil organic carbon stock per plot was estimated by using the methods described by Pang et al. (2020a). The soil total nitrogen, phosphorus and potassium stocks per plot were quantified according to the method of Pang et al. (2020b).